TiO2 nanowire arrays were generated on FTO glass by hydrothermal method, and then the TiO2/MoO3 composite film was prepared through electrodepositing MoO3 coating onto TiO2 nanowire arrays. The formation of TiO2/MoO3 composite films were confirmed by X-ray diffraction and scanning electron microscope. Li+ insertion/extraction in LiClO4/PC solution had been studied by electrochemical measurement technologies, and the optical transmittance of the samples in the colored and bleached states were used by UV-Vis NIR spectrophotometer. The parameters of switching time, reversibility, optical modulation and coloration efficiency were obtained. Then, the electrochromic properties were analyzed. The analysis showed that the electrochromic properties of the TiO2/MoO3 composite films were obviously enhanced for comparing with the TiO2 nanowire and MoO3 films. The effects of different thickness MoO3 coating on the discoloration properties of the composite films were studied. The results showed that TiO2/MoO3 composite films with 6 cycles of MoO3 thin films had the best electrochromic performance.